Schedule of Gain (Loss) Recognized in Earnings for Economic (Non-Designated) Derivative Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Feb. 28, 2014	Feb. 28, 2013	Feb. 28, 2014	Feb. 28, 2013
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	$ (1,446)	$ 4,753	$ (1,169)	$ 9,207
Commodity Contracts | Cost Of Goods Sold
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	(1,241)	3,611	(959)	7,844
Foreign Exchange Contracts | Miscellaneous Income (Expense)
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	$ (205)	$ 1,142	$ (210)	$ 1,363